1. The situation of a Community national who holds a postgraduate academic title which, awarded in another Member State, facilitates access to a profession or, at least, the pursuit of an economic activity, is governed by Community law, even as regards the relations between that national and the Member State whose nationality he possesses. Freedom of movement for workers and the right of establishment guaranteed by Articles 48 and 52 of the Treaty are fundamental rights in the Community system, and would not be fully realized if the Member States were able to refuse to grant the benefit of the provisions of Community law to those of their nationals who have taken advantage of its provisions to acquire vocational qualifications in a Member State other than that of which they were nationals. 2. Having regard to the fact that the need to protect a public which will not necessarily be alerted to abuse of academic titles not awarded according to the rules laid down in the country in which the holder of the title intends to make use of it constitutes a legitimate interest such as to justify a restriction, by the Member State in question, of the fundamental freedoms guaranteed by the Treaty, which have been exercised by one of its nationals by going to another Member State in order to undergo additional education and training, and in the absence of harmonization of the conditions under which a person holding a postgraduate academic title may make use of it in Member States other than the one in which it was awarded, Articles 48 and 52 of the Treaty must be interpreted as meaning that they do not preclude a Member State from prohibiting one of its own nationals, who holds a postgraduate academic title awarded in another Member State, from using that title on its territory without having obtained an administrative authorization for that purpose. The administrative procedure which the person concerned must follow for that purpose must be intended solely to verify whether the postgraduate academic title was properly awarded and it must be easily accessible and not call for the payment of excessive administrative fees any decision refusing authorization must be capable of being subject to judicial proceedings, the person concerned must be able to ascertain the reasons for the decision and the penalties prescribed for non-compliance with the authorization procedure must not be disproportionate to the gravity of the offence.